The present invention relates to a process for producing a hollow structure of carbon material and, more particularly, to a process permitting, without working after calcining, manufacture of a hollow structure having a desired shape and properties of carbon materials.
Heretofore, hollow structures of carbon materials have been produced by secondary working, such as by cutting a largesized block-shaped carbon material, and have been limited in their shape. Thus, only simple shapes, such as pipes, have been produced. In addition, waste materials, such as cutting chips, have been produced. Since the strength of carbon base materials is low, sheets cannot be produced, and impermeable carbon materials cannot be obtained. Because it is difficult to cut vitreous carbon materials having excellent impermeability to an arbitrary shape, hollow structures of such carbon materials are typically not provided by cutting. Although hollow structures of carbon materials can be manufactured by bonding calcined and worked products cut from a block to each other with a carbon cement made of graphite powder, resin and pitch and then recalcining the product, a high bonding strength cannot be provided due to ultrafine cracks, which occur due to calcining and contracting of the carbon cement. Moreover, the cost increases due to the necessity of the cutting step and the two calcining steps.